function [ ] = mx_eyelink_get_last_data( )
%MX_EYELINK_GET_LAST_DATA Gets an integer (unconverted) copy of the last/newest
% link data (sample or event) seen by eyelink_get_next_data().
%
% Parameters:
% buf 	Pointer to buffer (ISAMPLE, IEVENT, or ALL_DATA type).
% Returns:
% 0 if no data, SAMPLE_TYPE if sample, else event type code.
%
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% Copyright Eduardo Aponte 2013
% aponteeduardo@gmail.com